Rock-drill.



PATENTED MAY 26, 1908.

J. S. HARLOW.

ROCK DRILL.

. APPLIOATION FILED Jun. 1'3. 190?.

Z SHEETS-SHEET 1.

( m-wanton WWI ' a mum JAMES S. HARLOW, OF MINERAL, VIRGINIA.

BOOK-DRILL.

Specification of Letters Patent.

Patented May 26, 1908.

Application filed June 13, 1907. Serial No. 378,829.

To all whom it may concern:

Be it known that I, JAMEs S. HARLOW, citizen of the United States of America, residing at Mineral, in the county of Louisa and State of Virginia, have invented certain new and useful Improvements in Rock- Drills, of which the following is a specification.

This invention relates to rock drills and particularly to a valve controlling mechanism operated by the piston whereby the stroke of the valve actuating means may be regulated to cause the said piston to have a short stroke; though the normal stroke of the piston would be com aratively long or the same as that'ordinar y given to pistons of rock drills.

The pur ose of this invention, however, is to provi e novel means for shifting an extension of the valve controlling means into or out of the path of travel of the piston, whereby, when the said extension is in the path of travel of the piston, the stroke of the piston is shortened. In rock drills, this short stroke is especially" desirable where soft seams are encountered, as it permits a series of short strokes and consequent rotation of the drill in order that the holein the rock at the edge of the seam may be made uniform size to ermit the passage of the drill through the 11012 When turned at any of its angles of adjustment.

It is well known in practice, that where the drill encounters soft material, the rearward travel of the drill is retarded, owing to the fact that the drill is given an initial turn and the hole is so restricted as to arrest the rearward movement of the drill and difficulty is encountered in removing it. It has also been found in practice that the drills which are used as starters, sometimes wear to an unusual degree and the hole they produce is restricted to such an-extent that the drill of the next length cannot be applied and reciprocated.

By the use of a machine having a short stroke, the end of the piston can be ap lied to the drill by what is known as oose chucking and by starting the piston a series of short strokes will be applied to the end of the drill. The action of the piston on the drill will result in loosening the drill in the hole and the said drill can be then turned little by little until a cut is made sufficiently large to permit the free rotation of the drill in the hole. After this step, the drill may be secured to the end of the piston and the piston continued 'on the short stroke will operate the drill until the hole has reached a sufficient depth to permit the full stroke of the piston. When such result is accomplished, the piston may be then thrown on the long stroke and the drilling operation will proceed in the usual Way.

It is'an object of this invention to regulate a stroke, that the operator may control the valve operating mechanism by which the said valve may be thrown from side to side, while the piston is traveling a comparatively short distance, or the said operator may by suitably manipulating the controlling lever, set the parts to return the piston to the full stroke.

With the foregoing and other objects in view, the invention consists in the details of construction and in the combination and arrangement of parts to be hereinafter more fully set forth and described.

In describing the invention in detail, reference will be had to the accompanying drawing forming part of this speclfication wherein likecharaoters denote corresponding parts in the several views, in which Figure 1, is a side elevation of a rock drill operating device embodying the invention. Fig. 2, is a transverse sectional view on the line 22 of Fig. 1. Fig. 3, is a sectional view on the line 33 of Fig. 1. Fig. 4, is a vertical longitudinal section of the device.

Fig. 5, is an enlarged fragmentary sectional.

view illustrating a detail of the invention. Fig. 6, is a view in detail of a fragment of the crank lever employed in the invention. Fig. 7, is an enlarged view in end elevation of the sliding block.

In these drawings A, denotes a cylinder having ports a, and (1, extending from approximately its center to the ends thereof.

B, is the usual exhaust port having a rock{ ing tappet C, mounted therein, the said tap pet having .corner shoulders c and c, which are alternately engaged by the shoulders d and d, of the piston D. The operation of the device when the shoulders of the piston alternately contact with the tappet is the normal or full stroke of the piston.

In order to effect a short stroke of the piston, I have pivotally connected the lever E, to the tappet above its ivotal' pin 8, and have extended the said ever on an incline into the cylinder, where it may be adjusted to project into the path of travel of the shoulder on the forward end of the piston. When in this adjusted position, the shoulder of the piston will, of course, contact with the end of the lever at a point in advance of the tappetzand hence the said tappet will be rocked on its pivot and will operate the valve when the iston has moved rearward, a comparative y short stroke. By permitting the end of the lever to remain projected into the cylinder, the reciprocation of the piston on the short stroke will continue, but when the necessity for the short stroke has been removed and it is desired to return the piston to the long stroke, the end of the lever is elevated from the path of travel of the piston and is held in its elevated position during the will of the operator.

In order to provide for the manipulation of the parts to project and retract the lever, I have provided the sliding block F, having a slot through which the lever projects and as the said block is lowered or elevated, the end of the lever is thrown into the path of travel of the piston or elevated out of the path of travel of the piston. I prefer to recess the upper wall of the cylinder, as shown at forming uides for the block so that the said M block wil seat therein and be prevented from falling into the cylinder should it become disengaged from the operating lever G, which lever has its cranked end pivoted in the ear g, of the block. The lever is fulcrumed between the chest and the cylinder by an air tight joint and extends parallel, or approximately parallel, with the outer wall of the cylinder and terminates in a handle 9. The lever is sufficiently resilient to cause it to spring into the seat H, formed in the lug I, (to be hereinafter described) and the said lever is thereby retained in either position of adjustment until the said lever is sprung from engagement with the seat. Thus the 7 stroke of the piston is under the control of the operator, who controls the air and otherwise has to do with the operation of the drill.

As stated, the steam chest is provided with the usual ports extending to its ends I 'alining with the ports in the cylinder.

and the said ports are in communication with the valve chest, having a sliding valve K, with a recessed undersurface forming a seat for the end L, of the tappet, for it is through the oscillation of the tappet that the valve is reciprocated. The valve rests on a wear plate M, having suitable ports in communication with the ports in the intermediate plate N, which intermediate plate rests on the cylinder and has ports coinciding pr T 1e wear plate is comparatively thin and is provided for the purpose of being readily replaced without undue cost, owing to the fact that it is comparatively inexpensive and can be replaced without the renewal of any of the other parts.

The lug I, heretofore referred to, depends from the intermediate block and overlies the head of the pivotalpin e, on which the tappet oscillates. This retaining means obviates the use of bolts or threads for retaining the pivot in place and renders it readily renewable when it becomes worn to such an extent as toimp air its utility.

The pressure supply pipe 0, is of any ordinary construction, and the ports controlled by the valve are so well shown, it is believed that a detailed description of them will be unnecessary. It will be noted, however, that the port in the intermediate block is elongated as compared with ordinary ports. This arrangement is necessitated by the fact that the lever connected with the tappet and the block for operating the lever are interposed between the ports leading to the cylinder. The valve in this invention need not be of unusual size, as the parts may operate practically the same as in ordinary constructions by simply having the port elon gated, as stated.

What I claim is:

1. A rock drill operating device consisting of a cylinder having suitable ports, a piston therein having shoulders, a tappet to be engaged by the shoulders, a sliding valve controlling ports leadin to the cylinder operated by the tappet, aTever pivoted to the tappet and means for adjusting the end of the lever into and out of the path of travel of the shoulders of the piston.

2. In a rock drill operating device, a cylinder having ports, a valve for controlling the ports, a tappet pivoted to move the valve, means on the piston for engaging the tappet to swing it on its pivot,a member extending from the tappet with its end adapted to project into the path of travel of the tappet, actuating means on the piston and means for adjusting the position of'the end of the said member.

. 3. A rock drill operating mechanism consisting of a cylinder, a piston therein, a pivotally mounted tappet, means on the piston for oscillating the tappet, a valve actuated by the tappet, a member connected to the tappet having its end projecting into the.

path of travel of the piston, operatin means on the piston and means for adjusting said member.

4. In a rock drill operating mechanism, a cylinder having ports, a piston therein, a valve for controlling the ports alternately, a tappet for moving the valve, means on the piston for throwing the tappet in op osite directions, a member having its end projected into the ath of travel of the piston whereby, throug engagement of the piston, the said member is thrust, means for communicating the movement of the member to the tappet and means for adjusting theposition ofthe end of the member.

5. In a rock drill operating mechanism, a cylinder having ports, a valve for controlling the ports, means for reciprocating the valve, means whereby the movement of the piston operates the valve reciprocating device, means connected to the valve reciprocating device abutted by the piston in advance of the point at which said valve is. normally thrown and means for adjusting the position of the contacting surface thereof.

6. In a rock drill operating mechanism, a cylinder having ports, a piston therein, a valve chest, a wear plate therein, a valve slidable on the wear plate, means for reciprocating the valve, a piston for actuating the valve reciprocating mechanism, a member connected to the valve reciprocating means adapted to project into the path of travel of the piston for actuating the valve reciprocating means at a point in advance of that at which said valve is normally actuated and means for adjusting the position of the contacting surfaces thereof.

7. In a rock drill actuating mechanism, a cylinder havin ports, a valve for controlling the ports, vaIve actuating mechanism, a member pivoted to the valve actuating mechanism adapted to project into the path of travel of the piston and to take movement from the piston, a block in which the member is slidable and means for adjusting the positionof the block.

8. In a rock drill actuating mechanism, a cylinder having ports, a valve for controlling the orts, valve actuating mechanism, a mem er pivoted to the valve actuating mechanism adapted to project into the path of travel of a piston and to take movement 'from the piston, a block in which the member is slidable, means for adjusting the position of the block and means for limiting the downward movement of the block.

9. In a rock drill operating mechanism, a cylinder having ports, a tappet pivoted in the exhaust port of the cylinder, a wear plate, a valve thereon, a valve .chest thereover, a lever pivoted to the tappet, a block slidable in a seat in the cylinder and having an opening in which the lever is reciproeated, a piston having shoulders adapted to engage and oscillate the tappet and means for moving the block to project the end of the lever into the path of travel of a shoulder of the piston.

10. In a rock drill operating mechanism, a cylinder having ports, a ta pet pivoted in the exhaust port of the cylin er, a wear plate, a valve thereon, a valve chest thereover, a lever pivoted to the tappet, a block slidable in a seat in the cylinder and having an opening in which the lever is reciprocated, a cylinder having shoulders adapted to engage and oscillate the tap et means for moving the block to project t e end of the lever into the path of travel of a shoulder of the piston and means for rotating the said piston step by step.

In testimony whereof I afiix my signature in the presence of two Witnesses this 10 da of June, 1907.

JAMES S. HARLOW.

Witnesses:

V. W. TURNER, J. O. CARR. 

